Bending device for shaping glass for use in aircraft transparencies

ABSTRACT

A glass sheet used in the making of an aircraft windshield is shaped using the “cut-to-size” method instead of the “cut-after-bend” method. In a preferred aspect of the invention the “cut-to-size” method is practiced using a bending iron having a sheet shaping rail having a stationary shaping rail portion mounted on a support member and an articulating shaping rail portion pivotally mounted on the support member for movement from a non-shaping position to a shaping position.

RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.13/714,494 filed Dec. 14, 2012, in the names of John E. DeAngelis, YuJiao, Dennis D. Warren and Chao Yu, entitled BENDING DEVICE FOR SHAPINGGLASS FOR USE IN AIRCRAFT TRANSPARENCIES. U.S. patent application Ser.No. 13/714,494 in its entirety is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a bending device, usually referred to in theglass bending art as a bending iron, for shaping glass for use inaircraft transparencies, and more particularly relates to a bending ironfor symmetric/asymmetric shaping of glass sheets cut to size for use inthe manufacture of monolithic and/or laminated aircraft transparencies.

2. Presently Available Bending Device Technology

Bending devices, commonly referred to in the bending art as bendingirons, are well known for shaping glass sheets for use in themanufacture of monolithic and laminated transparencies for land, water,air and space vehicles. In general, the processing of glass sheets foruse in the manufacture of transparencies for land and water vehiclesusually include cutting a glass substrate to provide a glass sheethaving a predetermined size; moving a bending iron having the glasssheet through a furnace to heat soften and shape the glass sheet;controllably cooling the shaped glass sheet to anneal or heat strengththe shaped glass sheet, and using the shaped glass sheet in themanufacture of a transparency for a land or water vehicle. In general,the processing of glass sheets for use in the manufacture oftransparencies for air and space vehicles usually include cutting aglass substrate to provide a glass sheet having a predetermined size;moving a bending iron having the glass sheet through a furnace to heatsoften and shape the glass sheet; controllably cooling the shaped glasssheet to anneal the shaped glass sheet; cutting the shaped glass sheetto a second predetermined size; chemically strengthening the shapedglass sheet, and using the shaped glass sheet in the manufacture of atransparency for an air or space vehicle.

The difference between shaping a glass sheet for use with transparenciesfor land and water vehicles and shaping a glass sheet for use withtransparencies for air and space vehicles of interest in the presentdiscussion is that the glass sheet for use with transparencies for landand water vehicles is cut to size before bending, whereas a glass sheetfor use with transparencies for air and space vehicles is cut to an oversize before bending and cut to size after bending. For purposes ofclarity in the discussion of the glass window, the process for shaping aglass sheet for use with transparencies for land and water vehicles isalso referred to as “cut-to-size”, and the process for shaping a glasssheet for use with transparencies in air and space vehicles is referredto as “cut-after-bend”.

The cut-to-size process is acceptable for making transparencies for landand water vehicles because the glass sheets are thinner, and the opticalquality requirement for land and water vehicles is lower than theoptical quality requirement for aircraft transparencies. Moreparticularly, the thickness range for glass for automotivetransparencies is in the range of 1.8 to 3 millimeters (“mm”) whereasthe thickness range for glass for aircraft transparencies is in therange of 2 to 15 mm. Because the glass sheets used for makingtransparencies for air and space vehicles are thicker, the bending ironhaving the glass sheet remains in the furnace for a longer period oftime to heat the sheet to its bending temperature, which usually resultsin marring or marking surface areas of the glass sheet in contact withthe bending iron during the long heating periods. The marring or markingof the glass sheet can cause distortions on the surface of the glasssheets, which can make the optical quality of the glass unacceptable.Further, the displacement between the glass surface and the metalsurface of the bending iron under the high temperature condition willalso cause scratches in the glass surface, which results in unacceptabledefects.

As can now be appreciated, the marring and marking of the glass in thevision area is presently reduced or eliminated by providing a bendingiron and oversized glass sheet. After glass sheet is shaped, the shapedglass sheet is cut to size. The portions of the glass sheet cut awayhave the marring and markings from the bending iron.

As can now be appreciated it would be advantages to provide a bendingiron to shape glass sheets for air and space vehicles that does not havethe limitations of the presently available bending irons, e.g. but notlimited to, a bending iron that does not cause surface defects, whichcauses optical distortions in the vision area of the transparency; abending iron that can be used to make symmetric and asymmetric shapedglass sheets without having contact area distortions and scratches inthe vision area of the transparency, and a bending iron that can be usedin a cut-to-size process for shaping glass sheets to make transparenciesfor air and space vehicles.

SUMMARY OF THE INVENTION

This invention relates an improved method of shaping a glass sheet toprovide a shaped glass sheet for use in the manufacture of an aircraftwindshield. The method that is improved by the invention includes, amongother steps, the steps of:

(1) determining the peripheral dimensions of a flat glass sheet definedas desired peripheral dimensions such that when the flat glass sheethaving the desired peripheral dimensions is shaped, the shaped glasssheet for use in the manufacture of an aircraft windshield is provided;

(2) providing a flat glass sheet having peripheral dimensions defined asenlarged peripheral dimensions greater than the desired peripheraldimensions;

(3) positioning the flat glass sheet having the enlarged peripheraldimensions on shaping rails of a bending device such that the shapingrail of the bending device engages the sheet having the enlargedperipheral dimensions in an area of the sheet between the desiredperipheral dimensions and the enlarged peripheral dimensions;

(4) heating, shaping and cooling the sheet having the enlargedperipheral dimensions;

(5) cutting the shaped glass sheet having the enlarged peripheraldimensions to provide the shaped glass sheet for use in the manufactureof an aircraft windshield,

(6) using the shaped sheet from step (5) in the manufacture of theaircraft windshield, wherein the method including steps (1) through (6)is defined as a cut-after-bend method. The improvement includes, amongother steps, the steps of:

(a) practicing step (1);

(b) providing a flat glass sheet having the desired peripheraldimensions;

(c) positioning the flat glass sheet having the desired peripheraldimensions on shaping rails of a bending device such that the shapingrail of the bending device engages the sheet having the desiredperipheral dimensions in an area of the sheet within the desiredperipheral dimensions;

(d) heating, shaping and cooling the sheet having the desired peripheraldimensions;

(e) using the shaped sheet from step (d) in the manufacture of anaircraft windshield, wherein the method including steps (a) through (e)is defined as cut-to-size method,

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of a laminated aircraft transparencyillustrating the laminated structure of an aircraft transparency.

FIG. 2 is an isometric view of a shaped glass sheet having portionsremoved for purposes of clarity; the shaped glass sheet shaped inaccordance to the teachings of the invention. The shaped glass sheet canbe used in the fabrication of a laminated aircraft transparency of thetype shown in FIG. 1.

FIG. 3 is an isometric view of a non-limiting embodiment of a bendingdevice of the invention that can be used in the practice of theinvention to shape glass sheets, e.g. a shaped sheet of the type shownin FIG. 2.

FIG. 4 is an isometric view of an opposite side of the bending deviceshown in FIG. 3.

FIG. 5 is an isometric view of a flat glass sheet that can be shape inaccordance to the teachings of the invention to provide a shaped sheet,e.g. a shaped sheet of the type shown in FIG. 2.

FIG. 6 is a cross sectional view of a non-limiting embodiment of ashaping rail of the invention.

FIG. 7 is an isometric view of a non-limiting embodiment of a shapingrail that can be used in the practice of the invention.

FIG. 8 is a perspective view of a non-limiting embodiment of a corner ofa shaping rail of the invention.

FIG. 9 is a side elevated view of a non-limiting embodiment of a sheetretention and alignment member of the invention.

FIGS. 10 and 11 are enlarged isometric views of a pivot position of anend portion of a non-limiting embodiment of an articulating shaping railportion of the bending device of the invention shown in FIGS. 3 and 4.

FIG. 12 is an isometric view of a non-limiting embodiment of a biasingarrangement of the invention to move the articulating shaping railportion of the invention to shape a glass sheet.

FIG. 13 is an elevated plan view of a flat sheet that can be shape inaccordance to the teachings of the invention.

FIG. 14 is an elevated plan view of a shaped sheet that is shaped inaccordance to the teachings of the invention.

FIG. 15 is an isometric view of a non-limiting embodiment of bendingdevice of the invention that can be used in the practice of theinvention to, among other things, shape glass sheets of the type shownin FIG. 14.

FIG. 16 is an enlarged isometric view of a non-limiting embodiment of abiasing arrangement of the invention that is used in the practice of theinvention to apply a biasing force to the articulating rail portion ofthe bending device shown in FIG. 15.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, spatial or directional terms, such as “left”, “right”,“inner”, “outer”, “above”, “below”, and the like, relate to theinvention as it is shown in the drawing figures. However, it is to beunderstood that the invention can assume various alternativeorientations and, accordingly, such terms are not to be considered aslimiting. Further, as used herein, all numbers expressing dimensions,physical characteristics, processing parameters, quantities ofingredients, reaction conditions, and the like, used in thespecification and claims are to be understood as being modified in allinstances by the term “about”. Accordingly, unless indicated to thecontrary, the numerical values set forth in the following specificationand claims can vary depending upon the desired properties sought to beobtained by the present invention. At the very least, and not as anattempt to limit the application of the doctrine of equivalents to thescope of the claims, each numerical value should at least be construedin light of the number of reported significant digits and by applyingordinary rounding techniques. Moreover, all ranges disclosed herein areto be understood to encompass the beginning and ending range values andany and all subranges subsumed therein. For example, a stated range of“1 to 10” should be considered to include any and all subranges between(and inclusive of) the minimum value of 1 and the maximum value of 10;that is, all subranges beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, e.g., 1 to 3.3; 4.7 to 7.5;5.5 to 10, and the like.

Before discussing non-limiting embodiments of the invention, it isunderstood that the invention is not limited in its application to thedetails of the particular non-limiting embodiments shown and discussedherein since the invention is capable of other embodiments. Further, theterminology used herein to discuss the invention is for the purpose ofdescription and is not of limitation. Still further, unless indicatedotherwise in the following discussion, like numbers refer to likeelements.

For purposes of the following discussion, the invention will bediscussed with reference to shaping a sheet for an aircrafttransparency. As will be appreciated, the invention is not limited tothe material of the sheet, e.g. the sheet can be, but is not limited to,a glass sheet or a plastic sheet. In the broad practice of theinvention, the sheet can include any desired material having any desiredcharacteristics. For example, the sheet can be opaque, transparent ortranslucent to visible light. By “opaque” is meant having visible lighttransmission of 0%. By “transparent” is meant having visible lighttransmission in the range of greater than 0% to 100%. By “translucent”is meant allowing electromagnetic energy (e.g. visible light) to passthrough but diffusing this energy such that objects on the side oppositethe viewer are not clearly visible. In the preferred practice of theinvention, the sheet is a transparent glass sheet. The glass sheet caninclude conventional soda-lime-silicate glass, borosilicate glass, orlithium glass used in chemical tempering. The glass can be clear glass.By “clear glass” is meant non-tinted or non-colored glass.Alternatively, the glass can be tinted or otherwise colored glass. Theglass can be annealed, heat-treated or chemically tempered. In thepractice of the invention, the glass can be conventional float glass,and can be of any composition having any optical properties, e.g., anyvalue of visible transmission, ultraviolet transmission, infraredtransmission, and/or total solar energy transmission. By “float glass”is meant glass formed by a conventional float process. Examples of floatglass processes are disclosed in U.S. Pat. Nos. 4,744,809 and 6,094,942.

In the preferred practice of the invention, the glass is a cleartransparent glass of the type that can be chemically strengthened.Chemical strengthening or chemical tempering of glass involves anexchange of ions near the surface of the glass, e.g. a glass articlewith ions from an external source, typically a molten inorganic saltbath, to generate a zone near the surface of the glass which is in astate of compression relative to the interior portions of the glass. Adetailed discussion of chemical tempering is present in U.S. Pat. No.7,871,703, which patent is hereby incorporated by reference, and nofurther discuss regarding chemical tempering is deemed necessary. Aswill be appreciated, the invention is not limited to a clear transparentglass that can be chemically tempered, and clear transparent glassesthat can be thermally tempered, e.g. soda-lime-silicate glasses of thetypes disclosed in U.S. Pat. Nos. 8,268,741, and 8,304,358 can be usedin the practice of the invention and are hereby incorporated byreference.

In the preferred practice of the invention, the glass sheet is used inthe manufacture of monolithic or laminated transparencies for anaircraft. However as can be appreciated, the shaped glass sheet can beused in the manufacture of any type of transparency, such as but notlimited to windshields, windows, rear lights, sunroofs and moonroofs;laminated or non-laminated residential and/or commercial windows;insulating glass units, and/or transparencies for land, air, space,above water and under water vehicles. Non-limiting examples of vehicletransparencies, residential and commercial transparencies, and aircrafttransparencies and methods of making the same are found in U.S. Pat.Nos. 4,820,902; 5,028,759, 5,653,903; 6,301,858; and 7,335,421, whichpatents are hereby incorporated by reference.

Shown in FIG. 1 is a non-limiting embodiment of an aircraft windshield20 that has components that can be made by the practice of theinvention. The windshield 20 includes a first glass sheet 22 secured toa second glass sheet 24 by a first interlayer or sheet 26; the secondsheet 24 secured to a vinyl-interlayer or sheet 28 by a first urethaneinterlayer 30, and the second vinyl-interlayer 28 secured to a heatablemember 32 by a second urethane interlayer 34. An edge member or moisturebarrier 36 of the type used in the art, e.g. but not limited to asilicone rubber or other flexible durable moisture resistant material issecured to (1) peripheral edge 38 of the windshield 20, i.e. theperipheral edge 38 of the first and second sheets 22, 24; of the firstand second vinyl-interlayers 26, 28; of the first and second urethaneinterlayers 30, 34 and of the heatable member 32; (2) margins ormarginal edges 40 of outer surface 42 of the windshield 20, i.e. themargins 40 of the outer surface 42 of the first glass sheet 22 of thewindshield 20, and (3) margins or marginal edges 44 of outer surface 46of the windshield 20, i.e. margins of the outer surface 46 of theheatable member 32.

As is appreciated by those skilled in the art and not limiting to theinvention, the first and second glass sheets 22, 24; the first andsecond vinyl-interlayers 26, 28 and the first urethane interlayer 30form the structural part, or inner segment, of the windshield 20 and theouter surface 42 of the windshield 20 faces the interior of the vehicle,e.g. an aircraft (not shown), and the second urethane layer 34 and theheatable member 32 form the non-structural part, or outer segment, ofthe windshield 20, and the surface 46 of the windshield 20 faces theexterior of the aircraft. As is appreciated by those skilled in the art,the heatable member 32 provides heat to remove fog from, and/or to meltice on, the outer surface 46 of the windshield 20.

As can be appreciated the invention is not limited to the constructionof the windshield 20 and any of the constructions of aircrafttransparencies used in the art can be used in the practice of theinvention. For example and not limited to the invention, the windshield20 can include a construction wherein the vinyl interlayer 28 and theurethane interlayer 30 are omitted, and/or the sheets 22 and 24 areplastic sheets. Further, the cross section of the window 20 shown inFIG. 1 shows flat or non-shaped sheets, the invention is not limitedthereto and the window 20 can have a contour to match the contour of theouter surface of the aircraft in which the window is mounted.

Generally the glass sheets 22, 24 of the windshield 20 are clearchemically strengthened glass sheets; however, the invention is notlimited thereto, and the glass sheets can be heat strengthened or heattempered glass sheets. Further as is appreciated, the invention is notlimited to the number of glass sheets, vinyl interlayers or urethaneinterlayers that make up the windshield 20, and the windshield 20 canhave any number of sheets and/or interlayers.

With reference to FIG. 2 there is shown a shaped glass sheet 120 shapedwith a non-limited embodiment of a bending device or bending iron 122(see FIGS. 3 and 4) of the invention in accordance to the teachings ofthe invention. With reference to FIGS. 3 and 4 as needed, the bendingdevice or bending iron 122 includes a ridged main support member 124 tosupport a shaping rail 126 having a stationary shaping rail portion orstationary rail portion 128 and an articulating shaping rail portion orarticulating rail portion 130. The shaping rail 126 is discussed indetail below. The main support member 124 includes a frame 132preferably made of a ridged material, e.g. but not limited to 1 inchsquare hollow steel tubing having a wall thickness of ⅛ inch. The tubingforms an outer boundary of the frame 132. A cross beam 136 made of thehollow steel tubing has one end 138 joined to an inside surface 140 of aside 142 of the frame 132 (see FIG. 4). Opposite end 144 of the crossbeam 136 is joined to the inner surface 140 of opposite side 146 of theframe 132. The surface 140 faces the interior of the frame 132. Thetubing of the frame 132 and cross beam 136 of the support member 124 arejoined together in any convenient manner, e.g. by screws, adhesive orwelding, to provide the frame 132 with a predetermined configuration andsize compatible with the configuration of the shaping rail 126 asdiscussed below. In the preferred practice of the invention, the tubingof the frame 132 and cross beam 136 of the support member 124 are weldedtogether in any usual manner.

The discussion is now directed to the features of the shaping rail 126of the invention to shape a flat glass sheet 148 (see FIG. 5) to theshaped glass sheet 120 (see FIG. 2). As will be appreciated, theinvention is not limited to the embodiment of the shaping rail 126 ofthe invention shown in FIGS. 3 and 4 to provide the shaped sheet 120shown in FIG. 2, and the non-limited embodiment of the shaping rail 126shown in FIGS. 3 and 4 can be modified within the teachings of theinvention to shape the flat sheet 148 (see FIG. 5) to a shaped sheethaving a different contour from the contour of the shaped sheet 120shown in FIG. 2.

With reference to FIG. 2, in one non-limiting embodiment of theinvention, the shaped glass sheet 120 is used as one sheet of two sheetsof a laminated aircraft windshield. In general, the shaped sheet 120 hasa first end 150, an opposite second end 152, a first side 154 and anopposite second side 156 with the ends 150 and 152, and the sides 154and 156 of the sheet 120 defining the perimeter of the shaped sheet 120and the flat sheet 148 (see FIG. 5). The sheet 120 has a first portion158 extending from the end 150 to an imaginary line identified by thenumber 160, and a second portion 162 extending from the imaginary line160 to the second end 152 of the sheet 120. The first portion 158 of thesheet, e.g. the sheet 148 shown in FIG. 5 is shaped on the stationaryportion 128 of the shaping rail 126 and the second shaped portion 162 ofthe sheet 120 is shaped on the articulating rail portion 130 of theshaping rail 126 (see FIGS. 3 and 4).

With reference to FIGS. 3, 4 and 6 as needed, in one non-limitingembodiment of the invention, the stationary portion 128 of the shapingrail 126 on which the sheet 120 or 148 rests is a stainless steel bar166 having a thickness of ⅛ inch as measured between sides 168 and 169of the bar 166, and a length or height as measured between the ends 171and 172 of 2 inches. The end 171 of the steel bar 166 supporting theglass sheet 120 or 148 is cover with a metal weaved cloth 174 secured tothe sides 168 and 169 of the bar 166 in any convenient matter, e.g. bytack welding. In one non-limiting embodiment of the invention, the metalweaved cloth 174 is a stainless steel weaved cloth of the type sold byBekeart number NP400.

The stationary rail portion 128 of the shaping rail 126 is maintained ina fixed relationship to the main support member 124 by a plurality ofrigid support member 178 of the type used in the art, e.g. of the typedisclosed in U.S. Pat. No. 6,629,436, which patent is herebyincorporated by reference. In general and not limiting to the invention,the support members 178 have an end 180 secured to the support member124, and an opposite end 182 secured, in any convenient manner to thestationary rail portion 128 of the shaping rail 126. In the preferredpractice of the invention, the end 180 of the support members 178 iswelded to the inner surface 140 of the support member 124, and theopposite end 182 of the support members 178 have a flattened end 183with a hole (not shown). The hole of the post is aligned with a hole(not shown) in the stationary rail portion 128 of the shaping rail 126to receive a nut and bolt assembly 184 to secure the stationary railportion 128 of shaping rail 126 to the end 182 of the support members178 to maintain the stationary rail portion 128 of the shaping rail 126in a fixed space relationship to the main support member 124.

With reference to FIGS. 3 and 4, selected ones of the support members178 securing the stationary rail portion 128 of the shaping rail 126 tothe support member 124 have a re-enforcement rod 188 to providestability to the stationary rail portion of the shaping rail 126 duringthe heating and shaping of the glass sheet 120 or 148 supported on theshaping rail 126 of the support member 124. The invention is not limitedto the number of re-enforcement rods 188 used, and the number dependson, among other things, the expected temperature of the furnace, thetime the bending iron is in the furnace, the thickness of the supportmembers 178 and the heat absorption of the support members. In onenon-limiting embodiment of the invention, the bending iron was used toshape a lithium containing glass for an aircraft windshield. As isappreciated by those skilled in the art lithium containing glass has ashaping temperature of 1040° F., and soda-lime-silicate glass has ashaping temperature of 1090° F.

The support members 178 were made of stainless steel had a diameter of ⅜inch and a height of 9 inches. As can now be appreciated by thoseskilled in the art, the lengths of the supports are dictated by thefinal shape of the glass and vary depending on the curvature of thefinal product. The bending iron 122 had stainless steel re-enforcementrods 188 having a diameter of ⅜ inch and a height to provide support forthe support members 178. The side 142 of the main support member 124 had5 rigid support members 178; side 190 between the sides 142 and 146 ofthe main support member 124 had four rigid supports 178; and side 192(shown as front side in FIG. 4) opposite to the side 190 had six rigidsupport members 188. The side 146 of the main support member 124 isdiscussed with the discussion regarding the articulating rail portion130 of the shaping rail 126. The rigid supports 180 of the side 190 hadno re-enforcement rods 188 (see FIG. 3). The first and third rigidsupport members 178 counting from the corner of the sides 142 and 190 ofthe main support member 124 each had a re-enforcement rod. The side 192of the main support member 124 had six rigid support members. The twoouter and the two center support members 178 had a re-enforcement rod188.

As is appreciated, the invention is not limited to the manner in whichthe re-enforcement rods 188 are secured to their respective rigidsupport member 178. In the non-limiting embodiment of the inventionunder discussion, end 194 of the rigid support members 188 were weldedto the main support member 124 and opposite end 196 was welded to itsrespective support member 178.

With reference to FIGS. 3, 4, 7 and 8 as needed, in a non-limitingembodiment of the invention, the stationary portion 128 of the shapingrail 126 was made by cutting a flat strip 200 having contours 202 toprovide the stationary portion 128 of the shaping rail 126, and notches204 at corners, or expected corners 206 (see FIG. 8), of the stationaryportion 128 of the shaping rail 126, and notches 207 at each end 208 ofthe stationary portion of the shaping rail. The strip 200 is bent to theshape of the stationary rail portion 128 of the shaping rail 126 in anyconvenient manner. With reference to FIG. 8, a post 209 is welded to thesurface 169 of the bar 166, and a tungsten carbide block 210 is securedin position by the post 209. The notches 204 eliminate the metalbunching at the corners 206 when the strip 200 is bent. The tungstencarbide blocks 210 are secured in the notches at the ends 208 of the bar166 in any convenient manner. The tungsten carbide blocks 210 at thecorners and the ends 208 provide a non-friction surface to support theglass sheet 120 or 148 at the corners 206 and the ends of the stationaryportion 128 of the shaping rail 126. The height of the tungsten carbideblocks is preferable equal to or slightly higher than the height of thebar 166 having the metal weave cloth.

With reference to FIGS. 3, 4 and 9 as needed, secured on, and spacedfrom, the bar 166 of the stationary rail portion 128 of the shaping rail126 are sheet retention and alignment members 214. In the preferredpractice of the invention, the retention members 214 had a stainlesssteel core 215 and a carbon sheath 217; however, as can be appreciated,the retention members 214 can be one piece made of any material capableof withstanding sanding high temperatures, e.g. made of metal and nonmetallic material, e.g. plastic, tungsten carbide and carbon. Theretention and alignment members 214 had a configuration having acylindrical bottom portion 216 and a cone shaped top portion 218. Theretention members 214 were connected to the bar 166 of the stationaryportion 128 of the shaping rail 126 in any convenient manner, e.g. inthe practice of the invention an L-shaped threaded member 220 havinglong leg 222 of the L-shaped member 220 secured to the bar 166 of thestationary portion 128 of the shaping rail 126 by a pair of bolts 224threaded on the long leg 222 of the L-shaped member 220 with thestationary portion 128 of the shaping rail 126 between the bolts 224(see FIG. 9). With continued reference to FIG. 9, the cylindricalportion 216 of the retention member 214 extends above the stationaryrail portion 128 of the shaping rail 126. With this arrangement, whenthe flat glass sheet 148 to be shaped is placed on the shaping rail 126,peripheral edge 226 of the glass sheet 120 can slide down the surface ofthe cone shaped portion 218 of the alignment member 214, and thereafteralong the outer surface of the cylindrical portion 216 to align thesheet 148 with the stationary rail portion 128 of the shaping rail 126and to prevent the sheet 148 from sliding along the shaping rail 126away from the articulating rail portion 130 of the shaping rail 126during the sheet shaping process.

In a non-limiting embodiment of the invention, two retention andalignment members 214 were secured in spaced relationship to one anotherand 2 inches from the adjacent corner 206 on a segment 228 of thestationary portion 128 of the shaping rail 126 opposite to thearticulating rail portion 130 of the shaping rail 126 (see FIGS. 3 and4), and one retention and alignment member 214 was secured on a segment230 of the stationary rail portion 128 of the shaping rail 126 adjacentto and spaced 4 inches from the articulating rail portion 130 of theshaping rail 126, and one of the retention and alignment members 214 wassecured to a segment 230 of the stationary rail portion 128 of theshaping rail 126 adjacent to and spaced 4 inches from the articulatingrail portion 130 of the shaping rail 126. The retention members 214align the sheet 148 on the shaping rail. The alignment and retentionmembers 214 on the segment 228 also limit movement of the sheet 148 awayfrom the articulating rail portion 130 of the shaping rail 126 as thesheet 148 is shaped by the articulating rail portion 130. The alignmentand retention member 214 on the segment 230 of the stationary railportion 128 of the shaping rail 126 also limits movement of the sheet148 over the segment 230 of the stationary rail portion 128 of theshaping rail 126 as the articulating rail portion 130 of the shapingrail 126 moves to shape the sheet 148 in a manner discussed below.

As can now be appreciated, the invention is not limited to the number ofalignment members 214 secured on the stationary rail portion 128 of theshaping rail 126 and any number, e.g. 5, 7 or more can be used; further,the invention is not limited to the placement of the retention andalignment members 214 on the shaping rail 126, and the retention membercan be placed at any location of the shaping rail 126 where it can beexpected that the sheet 120 can move when the articulating rail portion130 of the shaping rail 126 moves to shape the sheet 148.

The discussion is now directed to the articulating rail portion 130 ofthe shaping rail 126. With reference to FIGS. 3, 4, 10 and 11 as needed,the articulating rail portion 130 includes a shaping rail section 240mounted on a support frame or cradle 242 by the rigid support member 178in a similar manner as the bar 166 of the stationary portion 128 of theshaping rail 126 is mounted on the main support member 124 of thebending iron 122. The support frame 242 is pivotally mounted asdiscussed below to upright members 244 and 245 of a U shaped frame 246securely mounted on the main support member 124 and cross beam 136 ofthe bending iron 122. The shaping rail section 240 is made of stainlesssteel bar 248 and shaped to have a generally L-shaped configuration(hereinafter also referred to as “L-shaped bar 248”). End 252 of thelong leg 250 of the L-shape bar 248 is aligned with the adjacent end 208of the stationary portion 128 of the shaping rail 126 (see FIG. 3), andend 254 of the short leg 256 of the L-shaped bar 252 is aligned withadjacent end 208 of the stationary portion 128 of the shaping rail 126(see FIG. 4) such that the shaping rail 126 forms a closed shaping rail126.

The L-shaped bar 248 in cross section has the same configuration anddimensions as the bar 166 of the stationary portion 128 of the shapingrail 126 (see FIG. 6). The metal weaved cloth 174 covers upper portionof the L-shaped bar 248 and is tack welded to the bar 248 in a similarfashion as the metal weaved cloth 174 is secured on the bar 166 of thestationary portion 128 of the shaping rail 126. The L-shaped bar 248 isformed in a similar fashion as the bar 166 of the stationary portion 128of the shaping rail 126 except that there is no notch at junction 260 ofthe long leg 250 and short leg 257 of the L-shaped bar 248 because thejunction 260 has a radius greater than the radius of the bends of thestationary portion 128 of the shaping rail 126. The larger radius at thejunction 260 minimizes, if not eliminates bunching of the L-shaped bar252 at the junction 248 when the straight bar is bent to the shape ofthe L-shaped bar 248.

As mentioned above, the support frame 242 is pivotally mounted on theupright members 244 and 245 of the U-shaped member 246. With continuedreference to FIGS. 3 and 4, the U-shaped frame 246 includes the uprightmembers 244 and 245 interconnected by center member 264. The centermember 264 overlays and is secured to the main support member 124 in anyconvenient manner, e.g. the central member 264 was connected to the mainsupport member 124 by welding. The center member had a length such thatthe shaping rail 126 was between the upright members 244 and 245 asshown in FIGS. 3 and 4.

The articulating rail portion 130 of the shaping rail 126 is pivotallymounted to the main support frame 124 in any convenient manner. Withreference to FIG. 3, the support frame 242 of the articulating portion130 had a generally L-shaped configuration with a long leg 270 and ashort leg 272. The long leg 270 of the L-shaped support frame 242 waspivotally mounted to the upright member 244 through an arrangement thatincluded an angle iron 274 having leg members 276 and 278, with the legmember 276 pivotally mounted to the upright member 244 in a mannerdiscussed below. End portion 280 of the long leg 270 of the supportframe 242 was curved generally corresponding to the curved end portionof the long leg 250 of the steel bar 248. The end portion 280 of thelong leg 270 of the support frame 242 is welded to the leg member 278 ofthe angle iron 274. A gusset plate 284 had end 286 welded to the longleg 270 of the support frame 242 and opposite end 288 of the gussetplate 284 welded to the end portion 280 of the long leg 270 of thesupport frame 242 as shown in FIG. 3. Further, as shown in FIG. 3, theupright member 244 included a grooved end 300 to receive the end portion280 of the leg member 276 of the angle iron 274. A bolt 302 of a nut andbolt assembly 304 passes through walls 306 of the grooved end 300 of theupright member 244 and through the end portion 280 of the leg member 276to pivotally mount the angle iron 274 to the upright member 244.

The discussion is now directed to pivotally mounting the articulatingrail portion 130 of the shaping rail 126 to the upright 245. Withreference to FIGS. 4, 10 and 11 as needed, the short leg 272 of thesupport frame 242 of the articulating rail portion 130 of the shapingrail 126 is secured to angle iron 308 in any convenient manner. Forexample and not limiting to the invention, end portion 310 of the shortleg 272 of the support frame 242 of the articulating rail portion 130was welded to leg member 312 of the angle iron 308 by way of metal rod313 (see FIG. 11). Other leg member 314 of the angle iron 308 is alsowelded to the short leg 272 of the support frame 242 of the articulatingportion 130 by way of a gusset plate 315 as shown in FIG. 11. Endportion 316 of the leg member 312 is pivotally mounted to the uprightmember 245 by the nut and bolt assembly 304 in a similar manner as theleg member 276 of the angle iron 274 is pivotally mounted to the uprightmember 244 as shown in FIG. 3.

With the leg members 276 and 314 of the angle irons 274 and 308,respectively, pivotally mounted to their respective upright member 244and 245 of the U-shaped frame 246, moving the support member 242 of thearticulating rail portion 130 of the shaping rail 126 in a clockwisedirection as viewed in FIG. 3, or in a counterclockwise direction asviewed in FIG. 4, lowers the articulating rail portion 130 of theshaping rail 126 to the sheet receiving position to receive the flatsheet 148 (see FIG. 5). Moving the support member 242 of thearticulating rail portion 130 of the shaping rail 126 in thecounterclockwise direction as viewed in FIG. 3, or in a clockwisedirection as viewed in FIG. 4, raises the articulating rail portion 130of the shaping rail 126 to the shaping position to shape the flat glasssheet 148 (see FIG. 5) to the shaped glass sheet 120 shown in FIG. 2.

The invention is not limited to the biasing facilities used in thepractice of the invention to move the articulating rail portion 130 ofthe shaping rail 126 from the non-shaping position to the shapingposition. With reference to FIGS. 3, 4, 10 and 11 as need, there isshown a biasing arrangement 320 that has been used in the practice ofthe invention to move the articulating portion 130 from the non-shapingposition to the shaping position. It is to be noted that portions of thebiasing facilities are missing from FIG. 4 for purposes of clarity.

The biasing arrangement 320 (FIG. 3) includes an elongated rod 322pivotally mounted at a position 324 between ends 326 and 328 of the rod322 in any convenient manner to an upright 330. In one embodiment of theinvention, end 332 of the upright 330 is welded to a plate 334, which iswelded to the frame 132 of the bending device 122. Opposite end 336 ofthe upright 330 has a groove 338 to receive the rod 322. Walls 340 ofthe groove 338 and the rod 322 at the position 324 have holes 342 toreceive nut and bolt arrangement 344, which includes a bolt 346 in theholes 342 of the walls 340 of the groove 338 and the hole in theposition 324 of the rod 322 and secured in position by nuts 348. Withthis arrangement, the rod 322 is pivotally mount to the upright 330 atposition 324 such that moving the end 326 of the rod 322 in a firstdirection, e.g. in the direction of arrow 350 moves the opposite end 328of the rod 322 in a second opposite direction, e.g. In the direction ofthe arrow 352 (see FIG. 3), or such that moving the end 326 of the rod322 in a third direction, e.g. in the direction of arrow 354 moves theopposite end 328 of the rod 322 in a fourth opposite direction, e.g. inthe direction of the arrow 356 (see FIG. 3).

A force biasing member or weight 360 is mounted adjacent one of the endsof the elongated rod 322, e.g. the end 326 (see FIG. 3) to continuouslybias the end 326 of the rod 322 in the direction of the arrow 350 toplace the articulating rail portion 130 in the shaping position, and tomove the opposite end, e.g. the end 328 of the rod 332 in the directionof the arrow 352. The invention is not limited to the mounting of theforce biasing member 360 on any particular end of the rod 322. In onenon-limiting embodiment of the invention, if the articulating railportion 130 of the shaping rail 126 is heavier at one end, the forcebiasing member 360 is mounted on the end of the rod adjacent the lighterend of the articulating rail portion 130 to reduce the weight or forcethat has to be applied to the articulating rail portion 130 to raise thearticulating rail portion 130. More particularly, and with reference toFIG. 3, the articulating rail portion 130 of the shaping rail 126 has anL-shape support 240. In this instance, the force biasing member 360 ispreferably mounted on the end 326 of the rod 322, and the end 328 of therod 322 is arranged to engage the articulating rail portion 130 at aposition adjacent the short leg 242 of the L-shape support 240 of thearticulating rail portion 130 in a manner discussed below. To raise thearticulating rail portion 130 in the direction of the arrow 352 to movethe articulating rail portion 130 to the shaping position.

In the non-limiting embodiment of the invention under discussion, theL-shape support 240 adjacent the junction of the long leg 270 and theshort leg 272 designated by the number 362 has a metal bar 364 havingend 366 welded to the position 362 of the L-shaped support frame 240.The end 328 of the elongated rod 332 passes under the bar 364 such thatmoving the end 326 of the rod 322 in the direction of the arrow 350moves the articulating rail portion 130 in the direction of the arrow352 to move the articulating rail portion 130 to the shaping positionand moving the end 326 of the rod 322 in the direction of the arrow 354movies the end 328 in the direction of the arrow 356 to move thearticulating portion 130 to the sheet receiving position or non-shapingposition.

The applied force of the force biasing member 360 is selected to applysufficient biasing force to raise the articulating rail portion 130 ofthe shaping rail 126 (see FIGS. 3 and 4) with the sheet 148 (see FIG. 5)supported on the shaping rail 126 and heated to its shaping temperature,and the biasing force should be insufficient to raise the articulatingrail portion 130 with the sheet 148 is supported on the shaping rail126. In one non-limiting embodiment of the invention, a glass, e.g. asoda-lime-silica glass, and a lithium glass having a thickness of 6millimeters and heated to their bending temperate were shaped using aforce biasing member 360 weighing 3 pounds. In another non-limitingembodiment of the invention, a glass, e.g. a soda-lime-silica glass, anda lithium glass, having a thickness of 14 millimeters, heated to theirbending temperature were shaped using a force biasing member 360weighing 5 pounds.

In the practice of the invention, a flat glass sheet 148 is placed onthe shaping rail 126 of the bending iron 122. Two ends, e.g. the ends150 and 152 (see FIG. 5) of the sheet 148 are moved against the threesheet retention and alignment members 214 to align the sheet 148 on theshaping rail 126 of the bending iron 122. The weight of the sheet 148moves the articulating rail portion 130 of the shaping rail 126 and theend 328 of the rod 322 in the direction of the arrow 356 and moves theend 326 of the rod 322 and the force biasing member 360 in the directionof the arrow 354. When the sheet 148 is heated to a temperature withinits shaping temperature range, the biasing force of the force applyingmember 360 moves the end 326 of the rod 332 in the direction of thearrow 350 to move the end 328 of the rod 322 in the direction of thearrow 352 to raise the articulating portion 130 of the bending iron 122(see FIGS. 3 and 4) to shape the sheet 148.

As the articulating rail portion 130 moves in the direction of the arrow352, the end 150 of the sheet 148 is prevented from moving off of theshaping rail 126 by the sheet retention and alignment members 214opposite to the articulating rail portion 130 (see FIGS. 3 and 4).Movement of the articulating rail portion 130 also moves the end 154 ofthe sheet against the sheet retention and alignment member 214. As cannow be appreciate, the sheet retention and alignment members 214maintain the sheet 148 in position on the shaping rail 126 during theshaping of the sheet 148 (see FIG. 5) to the sheet 120 (see FIG. 2).

It was noted that during the shaping of the glass sheet 148 that theglass sheet 148 would occasionally stick in the area of the articulatingrail portion 130 adjacent the juncture of the long leg 259 and the shortleg 256 of the L-shaped shaping rail of the articulating rail portion130. It is believed the sticking was due to the sheet slightly bendingover the shaping rail of the articulating rail portion 130 as thearticulating rail portion 130 was raised to shape the sheet 148. Toprevent the sheet 148 or 120 from being marred by the movement of thearticulating rail portion 130, a member 367 having a non-friction orreduced friction sliding surface 368 is provide at the curved corner ofthe shaping rail 240 of the articulating rail portion 130 as shown inFIGS. 3 and 4. Reducing or eliminating the sticking of the sheet duringthe raising of the articulating rail portion 130 reduces marring of thesheet surface, which can cause optical distortion of the glass. In onenon-limiting embodiment of the invention, the member 367 was made ofmetal, e.g. but not limited to stainless steel.

With continued reference to FIG. 4, the movement of the articulatingrail portion 130 during the shaping of the glass sheet 148 to obtain thedesired curvature is limited by a stop plate 370 secured on the mainsupport member 124 in the path of the end 326 of the rod 322. A cotterpin 372 is mounted on the end 326 of the rod 322 to prevent the forcebiasing member 360 from sliding off the rod 322.

As can now be appreciated, the invention is not limited to theembodiment discussed and variations in the embodiment can be whilemaintaining the features of the invention. For example and not limitingto the discussion the parts of the main support frame were joinedtogether by welding, however, the invention is not limited thereto andthe components of the bending iron can be secured by any type offasteners, e.g. but not limited to nut and bolt arrangements and screwsmade of a material, e.g. steel that can withstand the elevatedtemperatures of the glass shaping process while maintaining thestructural stability of the bending iron. Further, the end 328 of therod 322 is shown in FIGS. 3, 4 and 10 as having decreasing diameter sothat the contact area between the plate metal bar 364 and the end 328 ofthe rod 322 is minimized to reduce contact friction as the end 328 ofthe rod 322 moves along the edge of the metal bar 364, while maintainingthe structural stability of the end 328 of the rod 322, e.g. but notlimited to being thick enough to prevent bending of the end 328 of therod 322. In one non-limiting embodiment of the invention, the rod 322 atthe end 326 had a diameter of ¾ inch and at the end 328 had a diameterof ⅜.

The invention is not limited to the manner in which the end 328 of therod 322 of the biasing arrangement 320 (see FIGS. 3 and 4) is connectedto the articulating rail portion 130 of the shaping rail 126. Moreparticularly, and with reference to FIG. 12, there is shown anothernon-limiting embodiment of a biasing arrangement designated by thenumber 400 for moving the articulating portion 130 to the shapingposition. The biasing arrangement 400 includes a rod 402 having auniform diameter from end 404 to end 406 of the rod 402. The forcebiasing member 360 is mounted on the rod 402 between the pivot point 324and the end 404, and adjacent the end 404 of the rod 402. The rod 402 atis pivotally mounted at the position 324 to the upright member 330 in asimilar manner as the rod 322 was mounted to the upright member 330 (seeFIG. 3). The end 406 of the rod 402 is connected to end 408 of extensionrod 410 by two universal joints 412 and 414, and opposite end 416 of theextension rod 410 is welded to the juncture 362 of the long leg 270 andthe short leg 272 of the support frame 242 of the articulating railportion 130 of the shaping rail 126 (see FIGS. 3 and 4).

The force biasing member 360 can be secured in position on the end ofthe rod 402 (FIG. 12) or the rod 322 (FIGS. 3 and 4) in any convenientmanner, e.g. by a pressure fit, providing a screw 418 to pass throughthe force biasing member 360 to engage the rod, e.g. the rod 402 asshown in FIG. 12 and/or providing external threads 420 (only shown inphantom in FIG. 12) on the rod 402, and internal threads (not shown) inthe passageway 422 of the weight 360.

The discussion will now be directed to a bending iron having a shapingrail having two articulating portions to provide a shaped glass sheethaving an asymmetric shape, e.g. two different shaped curved sections.More particularly and not limiting to the invention, a bending iron toshape a flat glass sheet 500 (see FIG. 13) to a shaped glass sheet 502(see FIG. 14) having curved end portions 504 and 506. A non-limitingembodiment of a bending iron that can be used in the practice of theinvention to shape the flat sheet 500 to the shaped sheet 502 is shownin FIG. 15 and designated by the number 508. The bending iron 508 has ashaping rail 510 having a first stationary shaping rail portion 512 anda second stationary shaping rail 514 to shape center portion 516, i.e.the portion 516 of the sheet between the curved segments 504 and 506, afirst articulating shaping rail portion 518 to shape the curved segment504 and a second articulating shaping rail portion 520 to shape thecurved segment 506. The shaped sheet 502 can be used for a monolithic orin a laminated window of an aircraft.

The bending iron 508 includes a main support member 522 and a shapingrail support member 524. The shaping rail support member 524 is securedon the main support member 522 by welding. As shown in FIG. 15, theshaping rail support member 524 is space at different distances from themain support member 522 to provide a tilt to the shaping rail supportmember 524 such that gravity aids in keeping the sheets 500 and 502 onthe shaping rail 510 during the shaping of the sheet 500. The inventionis not limited to the manner in which the shaping rail support member524 is spaced and secured to the main support member 522. In one nonlimiting embodiment of the invention, corner 526 of the shaping railsupport member 524 is secured to the main support member 522 by avertical shim 528 welded to the shaping rail support member 524 and themain support member 522; at corner 530 of the shaping rail supportmember 524, the shaping rail support member 524 is secured to the mainsupport member 522 by welding a section of steel tubing 532 and plates534 to the shaping rail support member 524 and the main support member522 as shown in FIG. 15; the corner 536 of the shaping rail supportmember 524 is secure to the main support member 522 by welding a sectionof steel tubing 538 to the shaping rail support member 524 and the mainsupport member 522 as shown in FIG. 15, and the corner 540 of theshaping rail support member is welded directly to the main supportmember 522 as shown in FIG. 15.

The first stationary shaping rail portion 512 and the second stationaryshaping rail portion 514 are fabricated in a similar manner as thestationary shaping portion 128 of the shaping rail 126 (see FIGS. 3 and4) except that no bending was required for corners (see FIG. 8). Thefirst stationary shaping rail portion 512 and the second stationaryshaping rail portion 514 are secured to the shaping rail support member524 by the ridged support member 178, and the nut and bolt assembly 184in a similar manner as the stationary portion 128 of shaping rail 126was secured to the frame 132 (see FIGS. 3 and 4).

With reference to FIG. 15, the discussion is now directed to the firstarticulating shaping rail portion 518. The first articulating shapingrail portion 518 includes a shaping rail 542 having a generally U-shapeand is connected to a stabilizing bar 544 by the ridged support member178, and the nut and bolt assembly 184 in a similar manner as thestationary portion 128 of shaping rail 126 was secured to the frame 132(see FIGS. 3 and 4). Leg 546 of the first articulating shaping railportion 518 is pivotally mounted at pivot point 548 to end 550 of anupright 552 by a bolt and nut arrangement 554. Leg 556 of the firstarticulating shaping rail portion 518 is pivotally mounted at pivotpoint 558 to end 560 of an upright 562 by a nut and bolt arrangement564. End 566 of the upright 552 and end 568 of the upright 562 are eachwelded to the shaping rail support member 524. A strengthening bar 570has one end 572 connected to the pivot point 558 and end portion 574welded to the stabilizer bar 570.

A biasing device 576 discussed in more detail below is connected in amanner discussed below to move the first articulating shaping railportion 518 in a counterclockwise direction as viewed in FIG. 15 to movethe first articulating shaping rail portion 518 from the non-shapingposition to the shaping position.

With continued reference to FIG. 15, the discussion is now directed tothe second articulating shaping rail portion 520. The secondarticulating shaping rail portion 520 includes a shaping rail 590 havinga generally U-shape configuration and is connected to a stabilizing bar592 by the ridged support members 178, and the nut and bolt assembly 184in a similar manner as the stationary portion 128 of shaping rail 126was secured to the frame 132 (see FIGS. 3 and 4). Leg 594 of the secondarticulating shaping rail portion 520 is pivotally mounted at pivotpoint 596 to end 598 of an upright 600 by a bolt and nut arrangement602. Leg 604 of the second articulating shaping rail portion 520 ispivotally mounted at pivot point 606 to end 608 of an upright 609 by abolt and nut arrangement 610. The pivot arrangement at pivot point 606for the upright 609 of the second articulating shaping rail portion 520is similar to the pivot arrangement for the pivot point 548 for theupright 552 of the first articulating shaping rail portion 518 as shownin FIG. 15.

A biasing device 614 discussed in more detail below is connected in amanner discussed below to move the second articulating shaping railportion 520 in a clockwise direction as viewed in FIG. 15 to move thesecond articulating shaping rail portion 520 from the non-shapingposition to the shaping position.

The biasing device 614 shown in FIG. 15 includes a force biasing member620 mounted on a ridged L-shaped rod 622 having a long leg 624 and ashort leg 626. The force biasing member 620 is mounted on the long leg624 and secured in position by screws 628 passing through a collars 630mounted on the long leg 624 on each side of the force biasing member 620and engaging the long leg 624 of the rod 622. The short leg 626 of therod 622 is connected at end 632 to a first outer leg 634 of a U-shapedmember 636. A metal gusset plate 638 has one end welded to the short leg626 and an opposite end welded to the long leg 624 of the L-shaped rod622. A metal rod 640 has one end welded to the first outer leg 634 ofthe U-shaped member 636 and the opposite end welded to the L-shapedmember, e.g. but not limiting to the invention, the juncture of theshort leg 626 and the long leg 624 of the L-shaped rod 622. Second outerleg 642 of the U-shaped member 636 has its end 644 connected to thepivot point 596 and is welded to outer surface of the leg 594 of secondarticulating shaping rail portion 520.

With the above discussed arrangement of the biasing device 614, thebiasing force of the force biasing member 620 moves the secondarticulating shaping rail portion 520 in a clockwise direction as viewedin FIG. 15 to move the second articulating shaping portion 520 to theshaping position. The downward motion of the force biasing member 620 islimited by a stop plate 646 mounted on a metal support member 648. Themetal support member 648 has one end welded to the shaping rod supportmember 524 and the opposite end welded to the main support member 522.

With reference to FIGS. 15 and 16 as needed, the connection of thebiasing device 576 to the first articulating shaping rail portion 518 issimilar in construction to the connection of the biasing device 614 tothe second articulating shaping rail portion 520 presented above exceptthat the stop 646 is mounted on a metal strip 650 connected to thecorner 540 of the shaping rail support member 524. With this arrangementthe biasing force of the weight 620 of the biasing device 576 moves thefirst articulating shaping rail portion 518 in a counterclockwisedirection as viewed in FIG. 15 to move the first articulating shapingportion 518 to the shaping position. The stop plate 646 limits thedownward motion of the force biasing member 620 of the biasing device576.

Other variations as are known to those skilled in the art can beresorted to without departing from the scope of the invention as definedby the claims that follow.

What is claimed is:
 1. In a method of shaping a glass sheet to provide ashaped glass sheet for use in the manufacture of an aircraft windshield,the method comprising the steps of: (1) determining the peripheraldimensions of a flat glass sheet defined as desired peripheraldimensions such that when the flat glass sheet having the desiredperipheral dimensions is shaped, the shaped glass sheet for use in themanufacture of an aircraft windshield is provided; (2) providing a flatglass sheet having peripheral dimensions defined as enlarged peripheraldimensions greater than the desired peripheral dimensions; (3)positioning the flat glass sheet having the enlarged peripheraldimensions on shaping rails of a bending device such that the shapingrail of the bending device engages the sheet having the enlargedperipheral dimensions in an area of the sheet between the desiredperipheral dimensions and the enlarged peripheral dimensions; (4)heating, shaping and cooling the sheet having the enlarged peripheraldimensions; (5) cutting the shaped glass sheet having the enlargedperipheral dimensions to provide the shaped glass sheet for use in themanufacture of an aircraft windshield, (6) using the shaped sheet fromstep (5) in the manufacture of the aircraft windshield, wherein themethod including steps (1) through (6) is defined as a cut-after-bendmethod, the improvement comprising: (a) practicing step (1); (b)providing a flat glass sheet having the desired peripheral dimensions;(c) positioning the flat glass sheet having the desired peripheraldimensions on shaping rail of a bending iron such that the shaping railof the bending iron engages the sheet having the desired peripheraldimensions in an area of the sheet within the desired peripheraldimensions; (d) heating, shaping and cooling the sheet having thedesired peripheral dimensions; (e) using the shaped sheet from step (d)in the manufacture of an aircraft windshield, wherein the methodincluding steps (a) through (e) is defined as cut-to-size method.
 2. Themethod according to claim 1, wherein the bending iron of step (c)comprises: a support member; a sheet shaping rail comprising astationary shaping rail portion securely mounted on the support memberand an articulating shaping rail portion pivotally mounted on thesupport member; a force biasing member operative connected to thearticulating shaping rail portion to move the articulating shaping railportion from a non-shaping position to a shaping position, and aretention member to limit movement of a sheet to be shaped relative tothe stationary shaping rail portion when the force biasing member movesthe articulating shaping rail portion from the non-shaping position tothe shaping position.
 3. The method according to claim 2 wherein thestationary shaping rail portion of the bending iron has a first leg, asecond leg and a middle leg, the legs connected to one another toprovide the stationary shaping rail portion with a generally U-shapedconfiguration, and the articulating shaping rail shaping portion ispivotally mounted on the support member with one end of the articulatingshaping rail portion adjacent an end of the first leg of the stationaryshaping rail portion and an opposite end of the articulating shapingrail portion adjacent an end of the second leg of the stationary shapingrail portion, wherein moving the articulating shaping rail portion fromthe non-shaping position to the shaping position moves the articulatingshaping rail portion toward the middle leg of the stationary shapingrail portion, and wherein the retention member comprises at least onestop member to engage peripheral edge of the sheet to be shaped to limitmovement of the sheet to be shaped over the stationary shaping railportion toward the middle leg of the stationary shaping rail portion asthe articulating shaping rail portion moves from the non-shapingposition to the shaping position.
 4. The method according to claim 3,wherein the stationary shaping rail portion of the bending iron has afirst end spaced from a second end and the articulating shaping railportion comprises an L-shaped shaping rail securely mounted on a supportframe and a pair of spaced uprights mounted on the support member,wherein one upright is mounted on the support member adjacent the firstend of the stationary shaping rail portion and the second upright ismounted on the support member adjacent the second end of the stationaryshaping rail portion, wherein the support frame is pivotally mounted onthe uprights to move toward and/or over the ends of the stationaryshaping rail portion when the articulating shaping rail portion movesfrom the non-shaping position to the shaping position.
 5. The methodaccording to claim 4 wherein a metal plate is mounted to thearticulating shaping rail portion of the bending iron adjacent to thejuncture of the long leg and the short leg of the L-shaped shaping railfor ease of moving the sheet to be shaped over the L-shaped shaping railwhen the articulating shaping rail portion is moved by the force biasingmember from the non-shaping position to the shaping position.
 6. Themethod according to claim 2, wherein the articulating shaping railportion of the bending iron is a first articulating shaping rail portionand the retention member comprises an articulating shaping rail portiondefined as a second articulating shaping rail portion, wherein thestationary shaping rail portion comprises two elongated shaping railsspaced from one another and between the first and the secondarticulating shaping rail portions.
 7. The method according to claim 6,wherein moving the first articulating shaping rail portion from anon-shaping position to a shaping position moves the first articulatingrail portion toward the second articulating shaping rail portion, andmoving the second articulating shaping rail portion from a non-shapingposition to a shaping position moves the second articulating railportion toward the first articulating shaping rail portion.
 8. Themethod according to claim 1, wherein the step (c) of the cut-to-sizemethod comprises: applying a force to marginal edge portions of the flatglass sheet to shape the flat glass sheet while engaging the peripheraledge portions of the flat glass to limit movement of the flat glasssheet during the applying a force step.
 9. A shaped glass sheet shapedaccording to the method of claim 1 wherein the shaped glass sheet ismade using the cut-to-size method.